The subject matter disclosed herein relates to refrigerator appliances, and more particularly to increasing energy efficiency in such refrigerator appliances.
One common configuration of a refrigerator appliance is known as a bottom mount configuration. In a bottom mount configuration, the freezer compartment is located below the fresh food compartment.
In a traditional airflow system in such bottom mount refrigerators, air is drawn over an evaporator coil by an evaporator fan and thereby cooled. The evaporator coil and fan are located in the freezer compartment as part of an evaporator assembly. Note that the evaporator assembly is the part of the refrigeration system through which refrigerant passes to absorb and remove the heat in the compartments being cooled (e.g., freezer compartment and fresh food compartment).
The cooled air from the evaporator fan is blown into an evaporator fan cover assembly (e.g., 802 in FIG. 8). The evaporator fan cover assembly is substantially closed with the exception of a first opening configured to allow evaporator cooled air to be directed into the freezer compartment (e.g., 800 in FIG. 8), and a second opening configured to allow evaporator cooled air to be directed into a fresh food cooled air supply duct. The fresh food cooled air supply duct runs up the outside of the fresh food compartment to an opening at the top of the fresh food compartment in many designs and on the inside of the compartment in other designs.
Accordingly, a majority of the evaporator cooled air that is blown into the evaporator fan cover assembly is directed into the freezer compartment. However, some evaporator cooled air blown into the evaporator fan cover assembly is directed up into the fresh food cooled air supply duct to the opening at the top of the fresh food compartment. The evaporator cooled air enters the fresh food compartment through this opening.
Such a traditional evaporator fan cover assembly introduces a large amount of restriction and thus pressure drop into the airflow system, i.e., since the evaporator fan cover assembly is substantially closed and catches the high volume airflow directly from the evaporator fan before directing a majority of the airflow into the freezer compartment and a smaller portion of the airflow toward the fresh food compartment. However, this large amount of restriction and pressure drop causes the airflow system to work harder, thus reducing the efficiency of the refrigerator.